Spark-voltage generation mechanisms for gas lighters and the like in the prior arts utilize a cam mechanism operating in a series of actions that a hammer strikes a piezoelectric element and generates a high-voltage pulse by releasing a compressed spring, in which the spring is compressed and released by applying only one-way compression force, as described in the patent references below.
This piezoelectric mechanism is provided with apertures of the cam holes in both flanks of the inner box along which the hammer moves. A hammer pin connected with the hammer moves along the edge of the cam hole, at the same time, the hammer pin moves following the L-shaped cam-groove on the outer box. The combination of this movement enables the function of striking the piezoelectric element to generate the high-voltage pulse and igniting the gas by just pushing the mechanism in only one way.    Patent reference 1 Publication Jitsu Kou Shou62-18846    Patent reference 2 Publication Tokkai Hei 5-66014